Electro-optical device and electronic apparatus

ABSTRACT

The invention provides an electro-optical device that has luminescent elements of a long lifetime by preventing oxygen or moisture from entering to luminescent layers or electrodes even in case of an electrode-optical device provided with a number of luminescent layers and an electronic apparatus provided with the electro-optical device. The invention can include an electro-optical device having first electrodes on a base body, a plurality of element areas including element layers including at least one functional layers disposed above the first electrodes, a second electrode formed above the element layers, a surrounding sections disposed on the base body so as to cover outer sides of the element layers included the element areas in the nearest proximity of the periphery of the base body, and a gas-barrier layer covering over the second electrode. Outer sides of the surrounding sections can be covered with the second electrode, and the gas-barrier layer can be in contact with the base body.

This is a Divisional application of application Ser. No. 14/294,811filed Jun. 3, 2014, which is a Continuation of application Ser. No.12/461,110 filed Jul. 31, 2009, which is a Divisional of applicationSer. No. 11/798,743 filed May 16, 2007, which is a Continuation ofapplication Ser. No. 10/691,671 filed Oct. 24, 2003, which claimspriority to Japanese Patent Application No. 2002-311109 filed Oct. 25,2002. The entire disclosures of the prior applications are herebyincorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Technical Field of Invention

The present invention relates to an electro-optical device andelectronic apparatus provided with the electro-optical device.

2. Description of Related Art

Hitherto, an electro-optical device is known that includes an organicelectroluminescent (organic EL) display that has laminated structurecomposed of anodes, hole injection layers, luminescent layers made of anelectro-optical material such as an EL material, and cathodes on asubstrate. Organic electroluminescent elements constituting the organicEL display have problems in which the life time of the organic ELelements are shortened by the deterioration of a electro-opticalmaterial constructing the luminescent layer and the decrease ofconductivity of cathodes, due to oxygen or moisture.

SUMMARY OF THE INVENTION

As a typical technique for solving the problems, for example, a methodfor manufacturing organic EL elements including protective layers thatcovers luminescent layers or cathodes are known. (For example, referringto Japanese Unexamined Patent Application No. 8-111286 (FIG. 1).

In the method for manufacturing the organic EL elements, however, thecase of organic EL elements having a plurality of luminescent layers isnot described. This method is difficult to apply for an electro-opticaldevice provided with the display having a plurality of the organic ELelements. Therefore, prolonging the lifetime of a plurality of theluminescent elements (organic EL elements) included in theelectro-optical device can be difficult.

The present invention is achieved in view of at least theabove-mentioned problems, an object of the present invention can be toprovide an electro-optical device that has a long lifetime ofluminescent elements by surely and easily preventing oxygen or moisturefrom entering to luminescent layers or electrodes and an electronicapparatus provided with the electro-optical device.

To achieve the object, an electro-optical device can include firstelectrodes on a base body, a plurality of element areas includingelement layers having at least one functional layers disposed above thefirst electrodes, a second electrode formed above the element layers, asurrounding sections disposed on the base body so as to cover outersides of the element layers included the element areas in the nearestproximity of the periphery of the base body, and a gas-barrier layercovering over the second electrode, wherein outer sides of thesurrounding sections are covered with the second electrode, and thegas-barrier layer is in contact with the base body.

According to the electro-optical device, surrounding sections can beformed so as to cover outer faces of peripheries of element layersincluded in element areas. The outer faces of the surrounding sectionsare covered with second electrode. The second electrode is covered withgas-barrier layers. Particularly, the outer faces of the peripheries ofthe element layers included in element areas are triply sealed by thesurrounding sections, the second electrode, and the gas-barrier layer;hence, these layers surely prevents oxygen or moisture from enteringluminescent layers to block the deterioration of the electrodes and theelement layers due to oxygen or moisture. Thus, the lifetime of theluminescent elements is prolonged.

The second electrode or the gas-barrier layer are not needed for formingeach element layer (for example, the luminescent layers). Hence, finepatterning is not required, and a simple method for forming films may beperformed to increase productivity.

According to the electro-optical device, the element layers function bycarriers supplied from the first electrodes or the second electrode andpassing through the element layers. When the carriers pass through theelement layers, at least part of the element layers has the differentprobability of presence of electrons and holes, hence, the positive andnegative charges in the area may be out of balance. Material thatresides in the area has generally high reactivity, for example, reactswith oxygen or moisture to form defects in the area. The defective areabecomes carriers-capturing site to impair the function of the elementlayers. The element layers need to be sufficiently protected from thedeterioration factor such as oxygen or moisture and are protectedagainst oxygen or moisture by the surrounding sections or thegas-barrier layers.

Carrier-injection efficiency is significantly affected by the state ofelectrodes, hence, the electrodes need to be protected against thedeterioration factor such as oxygen or moisture in order toappropriately maintain the carrier-injection efficiency. As describedabove, the electrodes are also protected against oxygen or moisture bythe surrounding sections or the gas-barrier layers.

In the electro-optical device, the gas-barrier layer is preferablycomposed of an inorganic compound or a silicon compound.

In the case of the second electrode composed of, for example, aninorganic oxide such as indium tin oxide (ITO), a metal or an alloy,since the gas-barrier layer is composed of an inorganic compound or asilicon compound, the second electrode has excellent adhesion to thegas-barrier layer. Thus, the gas-barrier layer becomes a defect-free anddense layer that have an improved barrier property against oxygen ormoisture.

According to the electro-optical device, at least the face in contactwith the gas-barrier layer of the second electrode is preferablycomposed of an inorganic oxide.

In this case, the second electrode has excellent adhesion to gas-barrierlayer composed of an inorganic compound or a silicon compound to allowthe gas-barrier layer to become defect-free and dense layer that have animproved barrier property against oxygen or moisture.

According to the electro-optical device, an angle defined by the outerfaces of the surrounding sections and the base body is preferably 110°or more. In this case, the second electrode that covers the outer facesof the surrounding sections and gas-barrier layer have excellent stepcoverage; hence, the second electrode and the gas-barrier layer on theouter faces have high continuity.

According to the electro-optical device, the electro-optical device ispreferably an active matrix electro-optical device.

The second electrode is not necessary for each luminescent layer, hence,fine patterning is not required, and a simple method for forming filmsmay be performed to form the second electrode to increase productivity.

According to the electro-optical device, the gas-barrier layerpreferably has an oxygen concentration which is lower at a face adjacentto the second electrode than at the upper face. In this case, thisstructure can prevent oxygen in the gas-barrier layer from movingthrough the second electrode toward the luminescent layers; anddeteriorating the luminescent layer. Therefore, this structure canprolong the life of the luminescent layers.

According to the electro-optical device, a protective layer on thegas-barrier layer preferably covers the gas-barrier layer. In this case,the luminescent layers or the electrodes are protected by the protectivelayer to block the deterioration of the luminescent layers andelectrodes due to oxygen and moisture. Thus, the lifetime of theluminescent layers is prolonged.

According to the electro-optical device, the protective layer preferablyincludes a surface-protective sublayer on the surface of the protectivelayer. In this case, the surface-protective layer having functions thatare, for example, pressure resistance, wear resistance,anti-reflectivity for light, a gas-barrier property, and an ultravioletblocking property is formed; hence, the luminescent layers, theelectrodes, and gas-barrier layer are protected by thesurface-protective layer to prolong the lifetime of the luminescentlayers.

According to the electro-optical device, the protective layer ispreferably provided with a buffer layer that adheres to the gas-barrierlayer and has a buffer function against mechanical shock on thegas-barrier layer side. In this case, the buffer layer absorbs themechanical shock to the gas-barrier layer and the luminescent elementsbelow the gas-barrier layer and can prevent the gas-barrier layer andthe luminescent layers from deteriorating by the mechanical shock.

The buffer layer preferably includes silane coupling agents oralkoxysilane. In this case, the adhesion between the buffer layer andthe gas-barrier layer is improved; hence, a buffer function againstmechanical shock is improved.

The electronic apparatus according to the present invention can beprovided with the electro-optical device. Such electronic apparatus thatis provided with the electro-optical device including the luminescentelements that have a prolonged lifetime by blocking the deterioration ofthe luminescent layers and the electrodes due to oxygen or moisture,hence, the electronic apparatus has a prolonged lifetime.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numerals reference like elements, and wherein:

FIG. 1 is a schematic view showing a wiring diagram according to the ELdisplay of the present invention;

FIG. 2 is a plan view showing typical structure according to the ELdisplay of the present invention;

FIG. 3 is a cross-sectional view taken along the line A-B in FIG. 2;

FIG. 4 is a cross-sectional view taken along the line C-D in FIG. 2;

FIG. 5 is an enlarged cross-sectional view of a relevant part of FIG. 3;

FIGS. 6A to 6D are cross-sectional views describing a method formanufacturing EL display in process order;

FIGS. 7A to 7C are cross-sectional views describing processes followingFIGS. 6A to 6D;

FIGS. 8A to 8C are cross-sectional views describing processes followingFIGS. 7A to 7C;

FIGS. 9A to 9C are cross-sectional views describing processes followingFIGS. 8A to 8C;

FIGS. 10A to 10B are cross-sectional views describing processesfollowing FIGS. 9A to 9C;

FIG. 11 is an enlarged cross-sectional view of a relevant part of otherEL display according to the present invention;

FIGS. 12A to 12C are perspective views showing electronic apparatusaccording to the present invention; and

FIG. 13 is a graph showing the thickness dependence of the moisturepermeability for silicon compound films.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

According to an embodiment of an electro-optical device of the presentinvention, an electroluminescent (EL) display including of an ELmaterial as an example of an electro-optical material, in particular, anorganic EL material is described.

Referring to FIG. 1, a wiring structure of an EL display according tothe embodiment is described. An EL display 1 (electro-optical device) isan active matrix EL display including thin film transistors (TFTs) asswitching elements. As shown in FIG. 1, this EL display 1 can include aplurality of scanning lines 101, a plurality of signal lines 102 thatare disposed perpendicular to the scanning lines 101, and a plurality ofpower supply lines 103 that are disposed parallel to the signal lines102. Pixel-areas X are provided in the vicinity of respectiveintersections of the scanning lines 101 and the signal lines 102.

The signal lines 102 are connected to a data line driving circuit 100including a shift register, a level shifter, a video line, and an analogswitch. The scanning lines 101 are connected to a scanning-line-drivingcircuit 80 including the shift register and the level shifter.

Each of pixel areas X is provided with a switching TFT 112 having a gateelectrode to which a scanning signal is supplied through thecorresponding scanning line 101, a storage capacitor 113 retaining ashared pixel signal from the corresponding signal line 102 via theswitching TFT 112, a driving TFT 123 having a gate electrode to whichthe pixel signal retained in the storage capacitor 113 is supplied, apixel electrode 23 into which a driving current flows from the powersource line 103 when the pixel electrode is electrically coupled to thecorresponding power source line 103 via the driving TFT 123, and afunctional layer 110 disposed between the pixel electrode 23 and acathode 50. The pixel electrode 23, the cathode 50, and the functionallayer 110 define a luminescent element (organic EL element).

According to the EL display 1, driving a scanning line 101 allowsrespective switching TFTs 112 to be in an ON mode, and the potential ofthe signal lines 102 at this time is stored in the storage capacitors113. An ON or an OFF mode of the driving TFTs 123 is determined based onthe state of the storage capacitors 113. Then a current passes from thepower source lines 103 to the pixel electrodes 23 via channels of thedriving TFTs 123 and through the cathode 50 via the functional layers110. The functional layers 110 emit light in accordance with currentflowing in the functional layers 110.

Referring to FIGS. 2 to 5, a structure of the EL display 1 according tothe embodiment is described.

As shown in FIG. 2, the EL display 1 according to the embodiment is anactive matrix display provided with an insulating substrate 20. A pixelelectrode region (not shown) includes pixel electrodes connected toswitching TFTs (not shown) and arrayed into a matrix on the substrate20. Power source lines (not shown) are disposed around the regionincluding the pixel electrodes and are connected to the respective pixelelectrodes. A pixel area 3 (within alternate long and short dashed linesin FIG. 2) that is substantially rectangular in plan view is located atleast on the region including the pixel electrodes. According to thepresent invention, the substrate 20, as described in greater detailbelow, including the switching TFTs, various circuits, and interlayerinsulators and others formed on the substrate is referred to as a basebody (shown as reference numeral 200 in FIGS. 3 and 4).

A pixel area 3 is zoned an actual display area 4 in the center of thepixel area 3 (within alternate long and two short dashes line in FIG. 2)and a dummy area 5 disposed around the actual display area 4 (an areabetween the alternate long and short dashed lines and the alternate longand two short dashes line).

In an actual display area 4, display areas R, G, and B, each having apixel electrode, are arrayed into a matrix, at a distance in A-B and C-Ddirections.

Further, scanning-lines-driving circuits 80 and 80 are disposed on bothright and left sides of the actual display area 4 in FIG. 2. Thesescanning-lines-driving circuits 80 and 80 are disposed under the dummyarea 5.

Furthermore, a checking circuit 90 is disposed above the actual displayarea 4 in FIG. 2. The checking circuit 90 for checking the operatingstate of the EL display 1 has, for example, means for outputting theresults of checking to an external device (not shown) and inspects thedefects or quality of displays at the time of shipping or duringmanufacturing. The checking circuit 90 is also disposed under the dummyarea 5.

Driving voltages are applied from a predetermined power supply through adriving-voltage conductive lines 310 (see FIG. 3) and a driving-voltageconductive lines 340 (see FIG. 4) to the scanning-lines-driving circuits80 and 80 and the checking circuit 90. Driving-control signals and thedriving voltages for the scanning-lines-driving circuits 80 and 80 andthe checking circuit 90 are sent and applied from a predetermined maindriver to control the operation of the EL display 1 throughdriving-control-signal conduction lines 320 (see FIG. 3) anddriving-voltage conduction lines 350 (see FIG. 4). The driving-controlsignals are defined as command signals from the main driver forcontrolling output signals from the scanning-lines-driving circuits 80and 80 and the checking circuit 90.

As shown in FIGS. 3 and 4, the EL display 1 can include a plurality ofelectroluminescent elements (organic EL elements), each being providedwith the first electrode (the pixel electrodes 23), luminescent layers60 defined as functional layers according to the present invention, andthe second electrode (the cathode 50) formed on a base body 200.Further, these layers are covered with a gas-barrier layer 30.

According to the embodiment, the functional layers are defined as theluminescent layers 60, and an area composed of the element layersincluding the functional layers is defined as an elemental area (notshown). The functional layers according to the present invention aretypically luminescent layers (electroluminescent layer), and thefunctional layers may also be defined as carrier injection layers suchas hole or electron injection layers, or carrier conduction layers suchas hole or electron conduction layers. Furthermore, the functionallayers may also be defined as hole or electron blocking layers.

In the case of a top-emission EL display, luminescent light emerges fromthe gas-barrier layer 30 remote from the substrate 20, hence, thesubstrate 20 constituting the base body 200 may be a transparentsubstrate or an opaque substrate. Materials for the opaque substrate areceramics, such as alumina, sheets of metals, such as stainless steel,which are subjected to insulation treatment such as surface oxidization,thermosetting or thermoplastic resins, and films (plastic film) of thethermosetting or thermoplastic resins.

In the case of a back-emission EL display, luminescent light emergesfrom the substrate 20, hence, the substrate 20 may be a transparentsubstrate or a semitransparent substrate. Materials for the transparentor the semitransparent substrate are, for example, glass, quartz, andresins (plastic or plastic films), in particular, glass is preferablyused for the substrate. According to the embodiment, the top-emission ELdisplay emerges luminescent light from the gas-barrier layer 30, hence,the substrate 20 may be the opaque substrate composed of, for example,the opaque plastic film.

A plurality of the luminescent elements (organic electroluminescentelements) are disposed on a circuit section 11 that includes the drivingTFTs 123 for driving the pixel electrodes 23 on the substrate 20. Asshown in FIG. 5, the luminescent elements can include the pixelelectrodes 23 (the first electrodes) functioning as anodes, holeconduction layers 70 that inject or conduct holes from the pixelelectrodes 23, the luminescent layers 60 composed of an organic ELmaterial that is an electro-optical material, and the cathode 50 (thesecond electrode), formed in that order.

Under this structure, recombination of holes injected from the holeconduction layers 70 and electrons injected from cathode 50 in theluminescent layers 60 causes luminescent elements to emit luminescentlight.

According to the embodiment, the use of the top-emission EL display doesnot require transparent electrodes as the pixel electrodes 23, and thepixel electrodes 23 are formed of any suitable conductive material.

Materials forming the hole conduction layers 70 are polythiophenederivatives, polypyrrole derivatives, and doped polythiophene orpolypyrrole derivatives. For example, a dispersion liquid ofpoly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT/PSS)[trade name; Baytron P: manufactured by Bayer AG] is used, namelypoly(3,4-ethylenedioxythiophene) is dispersed in poly(styrene sulfonate)as a dispersion medium, and the dispersion is further dispersed intowater.

Materials for forming the luminescent layers 60 may be known luminescentmaterials that can fluoresce or phosphoresce. Preferably used are, forexample, (poly)fluorene (PF) derivatives, (poly)-p-phenylenevinylene(PPV) derivatives, polyphenylene (PP) derivatives, poly-P-phenylene(PPP) derivatives, polyvinylcarbazole (PVK), polythiophene derivatives,and polysilanes, such as polymethylphenylsilane (PMPS).

These polymeric materials may be doped with polymeric pigments such asperylene pigment, coumalin pigment, and rhodamine pigment, or lowmolecular weight materials such as rubrene, perylene,9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumalin 6, andquinacridone.

These polymeric materials may be replaced with known low-molecularweight materials.

An electron injection layer may be formed on the luminescent layer 60,if necessary.

As shown in FIGS. 3 to 5, according to the embodiment, the holeconduction layers 70 and the luminescent layers 60 are surrounded bylyophilic control layers 25 arrayed into a grid and organic bank layers221 on the base body 200, hence, the surrounded hole conduction layers70 and the luminescent layers 60 are defined as element layers formingsingle luminescent elements (organic EL elements).

According to the present invention, outermost periphery of the lyophiliccontrol layers 25 arrayed into a grid and the organic bank layers 221 onthe base body 200 are defined as surrounding sections 201 that cover theouter faces of the outermost periphery of the luminescent layers 60.

Regarding the organic bank layers 221 that are formed on the surroundingsections 201, the angle θ defined by outer faces 201 a of the organicbank layers 221 and the base body 200 is 110° or more. By an angle of110° or more, as described below, the cathode 50 formed on thesurrounding sections 201 and the gas-barrier layer 30 formed on thecathode 50 have excellent step coverage, hence, the cathode 50 and thegas-barrier layer 30 on the outer faces 201 a of the organic bank layers221 have high continuity.

As shown in FIGS. 3 to 5, the cathode 50 has a wider area than the sumof that of the actual display area 4 and the dummy area 5, and coversthe actual display area 4 and the dummy area 5. The cathode 50 is formedon the base body 200 so as to cover top faces of the luminescent layers60, the organic bank layers 221, the surrounding sections 201, and theouter faces 201 a of the surrounding sections 201. As shown in FIG. 4,the cathode 50 is connected to cathode power supply lines 202 that areformed on the periphery of the base body 200 and outer sides than theouter faces 201 a of the surrounding sections 201. The cathode powersupply lines 202 are connected to a flexible substrate 203. The cathode50 is connected to a driving IC (driving circuit) (not shown) formed onthe flexible substrate 203 through the cathode power supply lines 202.

According to the embodiment, the top-emission EL display requires atransparent cathode that transmits light, hence, the cathode 50 iscomposed of a transparent conducting material. The transparentconducting material is preferably indium tin oxide (ITO). In addition,amorphous transparent conductive materials such as indium zinc oxide(IZO; Registered trademark: manufactured by Idemitsu Kosan Co., Ltd.)may also be used. In this embodiment, the transparent conductingmaterial is ITO.

The gas-barrier layer 30 covers exposed areas of the cathode 50 on thebase body 200. The gas-barrier layer 30 prevents oxygen or moisture fromentering the inner layers, namely, the cathode 50 and the luminescentlayers 60. The gas-barrier layer 30 blocks the deterioration of thecathode 50 and the luminescent layers 60 due to oxygen or moisture.

The gas-barrier layer 30, for example, is composed of an inorganiccompound and is preferably composed of a silicon compound, such assilicon nitride, silicon oxynitride, or silicon oxide. In addition tothe silicon compound, the gas-barrier layer 30 may also be composed ofany other ceramic, for example, alumina, tantalum oxide, or titaniumoxide. The gas-barrier layer 30 composed of such an inorganic compoundhas high adhesion to the cathode 50 composed of ITO, hence, thegas-barrier layer 30 becomes a defect-free and dense layer that have animproved barrier property against oxygen or moisture.

The gas-barrier layer 30, for example, may be laminated structureincluding sublayers composed of different silicon compounds. Thegas-barrier layer 30 preferably includes a silicon nitride sublayer anda silicon oxynitride sublayer; or a silicon oxynitride sublayer and asilicon oxide sublayer formed in that order the cathode 50. In additionto these combinations, when the gas-barrier layer 30 includes aplurality of the silicon oxynitride sublayers that have differentcompositions, the gas-barrier layer 30 preferably has an oxygenconcentration which is lower at the bottom sublayer adjacent to thecathode 50 than at the upper layers.

With this structure, oxygen concentration of the cathode 50 side islower than that of the opposite side. Therefore, this structure canprevent oxygen in the gas-barrier layer 30 from moving through thecathode 50 toward the luminescent layers 60 that are disposed below thecathode 50, and deteriorating the luminescent layer 60. Therefore, thisstructure can prolong the life of the luminescent layers 60.

In place of the laminated structure, the gas-barrier layer 30 may becomposed of a heterogeneous composition that has continuously ordiscontinuously variable oxygen concentrations. In this case, thegas-barrier layer 30 is preferably has the oxygen concentration which islower at a face adjacent to the cathode 50 than at the upper face, forthe reason described above.

The thickness of the gas-barrier layer 30 is preferably between 10 nmand 500 nm. In the gas-barrier layer 30 having a thickness of less than10 nm, through holes may be formed by defects in the film or variationin thickness of the film to impair the gas-barrier property. In the caseof more than 500 nm, stress cracking may occur.

In this embodiment, the top-emission EL display requires that thegas-barrier layer 30 is transparent. The gas-barrier layer 30 has atransmittance of 80% or more in the visible light region by adjustingthe material properties and the film thickness.

As shown in FIG. 5, the circuit 11 is disposed under the luminescentelements. The circuit 11 is formed on the substrate 20 and is includedin the base body 200. A substrate protecting layer 281 as a base layercomposed principally of silica is formed on the substrate 20. Siliconlayers 241 are formed on the substrate protecting layer 281. Gateinsulating layers 282 composed principally of silica and/or siliconnitride are formed on the silicon layers 241.

Overlapping areas in the silicon layers 241 right below gate electrodes242 via the gate insulating layers 282 are defined as channel areas 241a. The gate electrodes 242 are part of the scanning lines 101 (notshown). A first interlayer insulator 283 that is composed principally ofsilica is formed on the gate insulating layers 282 that covers thesilicon layers 241 and the gate electrodes 242 formed on the gateinsulating layers 282.

Lightly-doped source areas 241 b and heavily-doped source areas 241S areformed in the source side of the channel areas 241 a in the siliconlayers 241 while lightly-doped drain areas 241 c and heavily-doped drainareas 241D are formed in the drain side of the channel areas 241 a,resulting in a lightly doped drain (LDD) structure. The heavily-dopedsource areas 241S are connected to source electrodes 243 through contactholes 243 a extending from the gate insulating layers 282 to the firstinterlayer insulator 283. This source electrodes 243 is part of thepower source lines 103 (referring to FIG. 1). In FIG. 5, the powersource lines 103 extend the position of the source electrode 243 in thedirection perpendicular to the drawing described above. On the otherhand, the heavily-doped drain areas 241D are connected to drainelectrodes 244, which are composed of the same layer as the sourceelectrodes 243, through contact holes 244 a extending from the gateinsulating layers 282 to the first interlayer insulator 283. The sourceelectrodes 243 are part of the power source lines 103.

The surface of the first interlayer insulator 283 having the sourceelectrodes 243 and the drain electrodes 244 is covered with a secondinterlayer insulator 284 composed principally of an acrylic resin, forexample. The second interlayer insulator 284 may also be composed ofsilicon nitride or silica instead of the acrylic resin. The pixelelectrodes 23 composed of ITO are formed on the surface of the secondinterlayer insulator 284 and are connected to the drain electrodes 244via contact holes 23 a disposed in the second interlayer insulator 284.As a result, the pixel electrodes 23 are connected to the heavily-dopeddrain areas 241D in the silicon layers 241 via the drain electrodes 244.

The thin film transistors (TFTs for driving circuits) included in thescanning-lines-driving circuits 80 and 80 and the checking circuit 90,namely N-channel or P-channel TFTs, for example, constituting a inverterincluded in a shift resistor among the driving circuits have a similarstructure to the driving TFTs 123 except for being not connected to thepixel electrodes 23.

The pixel electrodes 23, the lyophilic control layers 25, and organicbank layers 221 are formed on the surface of the second interlayerinsulator 284. The lyophilic control layers 25 are composed of lyophilicmaterials, such as silica as the major component. The organic banklayers 221 are composed of an acrylic resin or a polyimide resin.Opening sections 25 a provided in the lyophilic control layers 25, holeconduction layers 70 and luminescent layers 60 inside the bank openings221 a surrounded the organic bank layers 221 are formed in that order onthe pixel electrodes 23. The term “lyophilic” in this embodiment refersto having higher lyophilicity than other materials, such as an acrylicresin or a polyimide resin constituting the organic bank layers 221.

As described above, the circuit 11 is composed of layers up to thesecond interlayer insulator 284 on the substrate 20.

In the EL display 1 according to the embodiment, each of the luminescentlayers 60 can be formed such that luminescent wavelength bands of theluminescent layers 60 correspond to three primary colors of light inorder to display color images. For example, display areas R, G, Binclude the luminescent layers 60, i.e., red-luminescent layers 60Rcorresponding to red, green-luminescent layers 60G corresponding togreen, and blue-luminescent layers 60B corresponding to blue,respectively, in luminescent wavelength bands. A single pixel elementdisplaying color images is composed of these display areas R, G, B. Inboundaries of each color-display areas, black matrix (BM) layers (notshown) that are deposited by sputtering of metal chromium are formed,for example, between the organic bank layers 221 and the lyophiliccontrol layers 25.

Referring to FIGS. 6 to 10, typical method for manufacturing the ELdisplay 1 according to the embodiment is described. According to theembodiment, a top-emission EL display 1, as electro-optical device, isdescribed. Each cross-sectional view shown in FIGS. 6 to 10 is takenalong line A-B in FIG. 2.

As shown in FIG. 6(a), the substrate protecting layer 281 is formed onthe surface of the substrate 20. An amorphous silicon layer 501 isdeposited by an ICVD method or a plasma CVD method on the substrateprotecting layer 281 and then crystal grains are grown by a laserannealing method or rapid thermal processing to form a polysiliconlayer.

As shown in FIG. 6(b), the polysilicon layer is patterned byphotolithography to form island silicon layers 241, 251, and 261. Thesilicon layers 241 are formed within the display area to form thedriving TFT 123 connected to pixel electrodes 23. The silicon layers 251and 261 constitute P-channel and N-channel TFTs (TFTs for drivingcircuits) included in scanning-lines-driving circuits 80.

Then, the gate insulating layers 282 of silicon oxide layers with athickness of about 30 to 200 nm are formed over the entire surface ofthe silicon layers 241, 251, 261, and the substrate protective layer 281by plasma CVD or thermal oxidation. During forming the gate insulatinglayers 282 by thermal oxidation, the silicon layers 241, 251, and 261are crystallized to form polysilicon layers.

In the case of channel doping to the silicon layers 241, 251, and 261,boron ions are implanted with a dose of 1×10¹² cm² to form lightly-dopedP-type silicon layers that have an impurity concentration about 1×10¹⁷cm³ (calculated by impurities after activating annealing).

A mask for selective ion implantation is formed on part of channellayers of the P-channel TFTs and N-channel TFTs, then phosphorus ionsare implanted with a dose of 1×10¹⁵ cm². As shown in FIG. 6(c),impurities are heavily implanted into the patterning mask byselfalignment to form the heavily-doped source areas 241S, heavily-dopedsource areas 261S, the heavily-doped drain areas 241D, and heavily-dopeddrain areas 261D in the silicon layers 241 and 261.

As shown in FIG. 6(c), each conductive layer 502 for forming gateelectrodes is formed of a doped silicon film, a silicide film, or metalfilm made of aluminum, chromium, or tantalum over the entire surface ofthe corresponding gate insulating layer 282. The conductive layers 502have a thickness of about 500 nm. As shown in FIG. 6(d), gate electrodes252 to form P-channel TFTs for driving circuits, gate electrodes 242 toform pixel TFTs, and gate electrodes 262 to form N-channel TFTs fordriving circuits are formed by a patterning method. Thedriving-control-signal lines 320 (350) and a first layer 121 of cathodepower supply lines 202 are formed at the same time. In this case, thedriving-control-signal lines 320 (350) are disposed in the dummy area 5.

As shown in FIG. 6(d), the gate electrodes 242, 252 262 are used asmasks, phosphorus ions are implanted with a dose about 4×10¹³ cm² intothe silicon layers 241, 251, and 261. Therefore, impurities are lightlyimplanted into the gate electrodes 242, 252, and 262 by selfalignment.As shown in FIG. 6(d), the lightly-doped source areas 241 b and 261 b,the lightly-doped drain areas 241 c and 261 c are formed in the siliconlayers 241 and 261. Lightly-doped-impurity source areas 251S andlightly-doped-impurity drain area 251D are formed in the silicon layers251.

As shown in FIG. 7(a), a mask 503 for selective ion implantation isformed so as to cover the entire substrate except for the gateelectrodes 252 to form P-channel TFTs for driving circuits. Boron ionsare implanted into silicon layers 251 with a dose of about 1.5×10¹⁵ cm²through the mask 503 for selective ion implantation, Because the gateelectrodes 252 to form P-channel TFTs for driving circuits function as amask, impurities are heavily implanted into the gate electrodes 252 toform P-channel TFTs for driving circuits by selfalignment. Therefore,the lightly-doped-impurity source areas 251S and lightly-doped-impuritydrain area 251D are counter-doped to form source areas and drain areasof P-channel TFTs for driving circuits.

As shown in FIG. 7(b), the first interlayer insulator 283 is formed overthe entire substrate 20 and patterned by photolithography to formcontact holes C at positions corresponding to source and drainelectrodes for each TFT.

As shown in FIG. 7(c), a conductive layer 504 composed of a metal, forexample, aluminum, chromium, and tantalum is formed so as to cover thefirst interlayer insulator 283. The conductive layer 504 has a thicknessof about 200 to 800 nm. Mask layers 505 for patterning are formed on theconductive layer 504 so as to cover areas 240 a for forming source anddrain electrodes of each TFT, areas 310 a for forming thedriving-voltage conductive lines 310 (340), and areas 122 a for forminga second layer of the cathode power supply lines 202. Then theconductive layer 504 is patterned to form the source electrodes 243,253, and 263, the drain electrodes 244, 254, and 264 shown in FIG. 8(a).

As shown in FIG. 8(b), the second interlayer insulator 284 that coversthe first interlayer insulator 283 having these electrodes is formedwith polymeric material such as an acrylic resin. The second interlayerinsulator 284 preferably has a thickness of about 1 to 2 μm. The secondinterlayer insulator 284 may also be formed with silicon nitride thatpreferably has a thickness of 200 nm or silica having a thickness of 800nm.

As shown in FIG. 8(c), in the second interlayer insulator 284, positionscorresponding to the drain electrodes 244 for driving TFTs are etched tobe removed and form contact holes 23 a.

A conductive layer to be the pixel electrodes 23 is formed so as tocover the entire substrate 20. As shown in FIG. 9(a), the transparentconductive layer is patterned to form the pixel electrodes 23 connectedto the drain electrodes 244 through the contact holes 23 a in the secondinterlayer insulator 284 and dummy patterns 26 in the dummy area. InFIGS. 3 and 4, the pixel electrodes 23 and the dummy patterns 26collectively referred to as pixel electrodes 23.

The dummy patterns 26 are not connected to lower metal layers via thesecond interlayer insulator 284. The dummy patterns 26 are arrayed intoan island arrangement and have substantially the same shape as that ofthe pixel electrodes 23 formed in the actual display area. The dummypatterns 26 may also be different from the arrangement of the pixelelectrodes 23 formed in the actual display area. In this case, the dummypatterns 26 at least include dummy patterns formed above thedriving-voltage conductive lines 310 (340).

As shown in FIG. 9(b), the lyophilic control layers 25, which areinsulating layers, are formed on the pixel electrodes 23, the dummypatterns 26, and the second interlayer insulator. In addition, thelyophilic control layers 25 are partly open on the pixel electrodes 23,allowing holes to move from the pixel electrodes 23 through the openingsections 25 a (see FIG. 3). On the dummy patterns 26 not having theopening sections 25 a, the lyophilic control layers 25, which areinsulating layers, function as hole-conduction-blocking layers, hence,holes can not move. In the lyophilic control layers 25, BM layers (notshown) are formed in concave areas between two different pixelelectrodes 23, specifically, BM layers are formed on the concave areasof the lyophilic control layers 25 by sputtering with metal chromium.

As shown in FIG. 9(c), the organic bank layers 221 are formed onpredetermined positions of the lyophilic control layers 25, inparticular, so as to cover the BM layers. Specifically, in a method forforming the organic bank layers, a solution containing a resist such asan acrylic resin or a polyimide resin in a solvent is applied by anyapplication method, for example, spin-coating or dip-coating, to formorganic layers. Any organic material that is insoluble in a solvent forink described below and is easily patterned by etching or the like maybe used for the material for forming the organic layers.

The organic layers are patterned by photolithography or etching to formbank openings 221 a in the organic layers for forming the organic banklayers 221 having side walls facing to the bank openings 221 a. Inparticular, the outermost peripheries of the organic bank layers 221,namely, outer faces 201 a of the surrounding sections 201 according tothe present invention described above, preferably have an angle θdefined by the outer faces 201 a and the base body 200 is 110° or more.This angle allows the cathode 50 formed on the surrounding sections 201and the gas-barrier layer 30 formed on the cathode 50 to have good stepcoverage.

In this case, the organic bank layers 221 at least include organic banklayers formed above the driving-control-signal lines 320.

Lyophilic areas and lyophobic areas are formed on the organic banklayers 221. According to the embodiment, each of these areas is formedby plasma treatment. Specifically, the plasma treatment includes a stepof preheating; a step of enhancing ink affinity by modifying thesurfaces of the organic bank layers 221, the wall faces of the bankopenings 221 a, electrode faces 23 c of the pixel electrodes 23, and thetop surfaces of the lyophilic control layers 25 to lyophilic properties;a step of enhancing ink repellency by modifying the top surfaces of theorganic bank layers 221 and the walls of the bank openings 221 a tolyophobic properties; and a step of cooling.

The substrate (the substrate 20 including bank and the like) is heatedat a predetermined temperature, for example, about 70 to 80° C. and, inthe ink affinity enhancing step, the substrate is treated by plasma(oxygen plasma treatment) using oxygen as a reactive gas in theatmosphere. Then, in the ink repellency enhancing step, the substrate istreated by plasma (tetrafluoromethane plasma treatment) usingtetrafluoromethane as a reactive gas in the atmosphere, and thesubstrate heated during plasma treating is cooled to a room temperature.The steps impart lyophilicity and lyophobicity to predetermined areas.

Although electrode faces 23 c of the pixel electrodes 23 and thelyophilic control layers 25 are affected somewhat by tetrafluoromethaneplasma treatment, ITO that is the material for the pixel electrodes 23and silica and titanium dioxide that are materials for the lyophiliccontrol layers 25 have poor affinity to fluorine. Thus, hydroxyl groupsimparted by the ink affinity enhancing step are not substituted forfluorine, and lyophilicity is maintained.

The hole conduction layers 70 are formed by a step of forming the holeconduction layers. In the step of forming the hole conduction layers,material for hole conduction layers is applied on the electrode faces 23c by a spin-coating method or a droplet discharging method such as anink-jet method followed by drying and heat treatment to form the holeconduction layers 70 on the pixel electrodes 23. In the case ofselective application of the material for the hole conduction layers by,for example, an ink-jet method, an ink-jet head (not shown) is filledwith the material for the hole conduction layers and a dischargingnozzle of the ink-jet head is opposed to the electrode faces 23 cdisposed in the opening sections 25 a formed on the lyophilic controllayers 25. Droplets whose amount per single droplet is controlled aredischarged from the discharging nozzle to the electrode faces 23 c,while the ink-jet head and the substrate (the substrate 20) arerelatively moved.

Drying treatment for the discharged droplets evaporates the dispersionmedium or solvent in the material for the hole conduction layers to formthe hole conduction layers 70.

The droplets discharged from the discharging nozzle spread over thelyophilic electrode faces 23 and enter the opening sections 25 a on thelyophilic control layers 25. The droplets repel from the top faces ofthe organic bank layers 221 that have ink repellency without adhesion.When the droplets are discharged onto areas that are not predeterminedof the top faces of the organic bank layers 221, the droplets arerepelled from the top faces, entering the opening sections 25 a on thelyophilic control layers 25.

Steps after the step of forming the hole conduction layers arepreferably performed in inert gas such as nitrogen or argon in order toprevent the hole conduction layers 70 and the luminescent layers 60 frombeing oxidized.

The luminescent layers 60 are formed by the step of forming theluminescent layers. In the step of forming the luminescent layers, thematerial for forming the luminescent layers is discharged onto the holeconduction layers 70 by, for example, an ink-jet method followed bydrying and heat treating, for forming the luminescent layers 60 in thebank openings 221 a formed in the organic bank layers 221. In the stepof forming the luminescent layers, solvents used as the material forforming the luminescent layers are nonpolar solvents that not dissolvethe material composing the hole conduction layers 70 in order to preventredissolution of the hole conduction layers 70.

In the step of forming the luminescent layers, for example, materialsfor the luminescent layers to emit blue (B) light are selectivelyapplied on the display areas for blue light by the ink-jet method anddried. Similarly, the materials to emit green (G) light and red (R)light are selectively applied on the display areas for green and redareas, respectively, and dried.

As described above, an electron injection layers may be formed on theluminescent layer 60, if necessary.

As shown in FIG. 10(a), the cathode 50 is formed by the step of formingthe cathode layer. The cathode 50 can be composed of ITO formed byphysical vapor deposition such as vapor deposition. The cathode 50 isformed so as to cover not only the top of the luminescent layers 60, theorganic bank layers 221, and the surrounding sections 201, but also theouter faces 201 a of the surrounding sections 201.

As shown in FIG. 10(b), the gas-barrier layer 30 is formed so as tocover the entire cathode 50 exposed on the base body 200, constitutingthe EL display (electro-optical device) according to the presentinvention. The gas-barrier layer 30 is preferably formed by physicalvapor deposition, such as sputtering or ion plating, and then bychemical vapor deposition, such as plasma chemical vapor deposition(CVD). The physical vapor deposition such as sputtering or ion platinggenerally provides a film having relatively high adhesion even to asurface of a different composition, but has the drawbacks that theprovided film is granular, is liable to cause defects, and is liable tobecome highly stressed coatings. On the other hand, chemical vapordeposition provides a high-quality film that exhibits low stress, a goodstep-coverage, reduced defects, and a densed structure, but has pooradhesion or formability to a surface of the substrate of a differentcomposition. For example, a film is formed by physical vapor depositionup to a half or more of the required film thickness; then, the defectivefilm formed by the physical vapor deposition is compensated by chemicalvapor deposition; allowing the gas-barrier layer 30 having excellentgas-barrier property (for oxygen or moisture) as an overall film to formin a relatively short time.

The gas-barrier layer 30, as described above, may be composed of asingle layer composed of a homogeneous material, a plurality of layerscomposed of different materials, or a single layer having a compositionthat continuously or discontinuously varies across the thickness.

In the case of the gas-barrier layer 30 having a laminated structure ofa plurality of layers composed of different materials, the inner layer(layers closer to the cathode 50) formed by physical vapor deposition ispreferably composed of silicon nitride or silicon oxynitride, whereasthe outer layer formed by chemical vapor deposition is preferablycomposed of silicon oxynitride or silicon oxide.

The inner layers is formed by physical vapor deposition, as follows: asmall amount of oxygen is supplied into a film-forming device at aninitial stage; then, the amount of oxygen supplied is continuously ordiscontinuously increased; thereby, the gas-barrier layer 30 has anoxygen concentration profile which is lower at a side adjacent to thecathode 50 (inner side) than at the outer side.

The gas-barrier layer 30 may be formed by a single film-forming method.In this case, the gas-barrier layer 30 is preferably formed so as tohave an oxygen concentration profile which is lower at a side adjacentto the cathode 50 (inner side), as described above.

In this EL display 1, the surrounding sections 201 cover the outer facesof the outermost periphery of the luminescent layers 60, the cathode 50covers the outer faces of the surrounding sections 201, and thegas-barrier layer 30 covers the cathode 50 exposed on the base body 200,in particular, the outer faces of the luminescent layers 60 are triplysealed by the surrounding sections 201, the cathode 50, and thegas-barrier layer 30 to surely prevent oxygen and moisture from enteringthe luminescent layers 60. Thus, the cathode 50 and the luminescentlayer 60 are protected from the deterioration due to oxygen and moistureto prolong the lifetime of the luminescent elements.

An area of the gas-barrier layer 30 that is in contact with the basebody 200 is composed of a silicon compound. Even if the substrate 20constituting the base body 200 is made of a permeable resin, the entireoutsides of the luminescent elements are sealed by the gas-barrier layer30 and the interlayer insulator formed on the substrate 20 to prolongthe lifetime of the luminescent elements.

In the active matrix EL display, the cathode 50 and the gas-barrierlayer 30 are not required for each luminescent element, hence, finepatterning is not required for the cathode 50 and the gas-barrier layer30, and these films may be formed by a simple method with highproductivity.

The above-described EL display 1 is the top-emission EL display,however, the present invention is not limited to the embodiment. Thepresent invention is also applicable to a back-emission EL display andan EL display that emits light from both faces. Particularly, theback-emission EL display does not require a transparent electrode as thecathode 50. In such case, at least the face of the cathode 50 in contactwith the gas-barrier layer 30 is preferably composed of an inorganicoxide.

In this case, the face of the cathode 50 in contact with the gas-barrierlayer 30 is composed of an inorganic oxide, the cathode 50 has excellentadhesion to the gas-barrier layer 30 composed of an inorganic compoundor a silicon compound, hence, the gas-barrier layer 30 is free fromdefects and is a dense layer that has improved barrier property againstoxygen or moisture.

In the case of the back-emission EL display or the EL display that emitslight from the both faces, the switching TFTs 112 or the driving TFTs123 in the base body 200 are formed directly below the lyophilic controllayer 25 and the organic bank layers 221, not directly below theluminescent elements, thereby, the aperture ratio is preferablyincreased.

In this EL display 1, the first electrodes function as anodes and thesecond electrode functions as cathode according to the presentinvention. Alternatively, the EL display may have an inverse structurein which the first electrodes function as cathodes and the secondelectrode functions as anode. In this case, the positions of theluminescent layers 60 and the hole conduction layers 70 must beexchanged.

In the embodiment, the EL display 1 is applied to the electro-opticaldevice according to the present invention, however, it should beunderstood that the present invention is not limited to the embodiment.The present invention is applicable to any type of electro-opticaldevice as long as the second electrode is basically disposed on theoutside of the base body.

In the EL display 1, the gas-barrier layer 30 is the outermost layer andmay be sealed by a sealed substrate or a sealing can as conventionallyperformed.

FIG. 11 shows the embodiment in which a protective layer 204 is formedso as to cover the gas-barrier layer 30 as an example of sealing theoutside of the gas-barrier layer 30. The protective layer 204, in thisembodiment, is composed of a buffer sublayer 205 on the gas-barrierlayer 30 and a surface protective sublayer 206 disposed on the bufferlayer 205.

The buffer sublayer 205 adheres to the gas-barrier layer 30, can absorbmechanical shock from the outside, and is formed of an adhesive composedof, for example, a urethane resin, an acrylic resin, an epoxy resin, anda polyolefine resin. The adhesive has a low glass transition temperatureand is more flexible than the material for the surface protective layer206. A silane coupling agent or alkoxysilane is preferably added to theadhesive. In this case, the adhesion between the buffer layer 205 andthe gas-barrier layer 30 is improved; hence, buffer function againstmechanical shock is improved. Particularly, in the case of thegas-barrier layer 30 composed of a silicon compound, adhesion betweenthe gas-barrier layer 30 and the buffer layer 205 is improved by asilane coupling agent or alkoxysilane, hence, the gas-barrier layer 30has an improved gas-barrier property.

The surface protective layer 206 is formed on the buffer layer 205 toconstitute the surface of the protective layer 204 and has at least onefunction among pressure resistance, wear resistance, anti-reflectivityfor external light, a gas-barrier property, and an ultraviolet blockingproperty. The surface protective layer 206 is composed of a polymericlayer (a plastic film), a diamond-like carbon (DLC) layer, and glass.

In the EL display according to this embodiment, the top-emission ELdisplay requires the transparent surface protective layer 206 and thetransparent buffer layer 205. The back-emission EL display, however,does not require.

The protective layer 204 which is provided on the gas-barrier layer 30,can protect the luminescent layers 60, the cathode 50, and thegas-barrier layer; due to pressure resistance, wear resistance,anti-reflectivity for external light, a gas-barrier property, and aultraviolet blocking property of the surface protective layer 206,hence, the lifetime of the luminescent layers is prolonged.

When the buffer layer receives mechanical shock from the exterior, thebuffer layer 205 absorbs the mechanical shock to the gas-barrier layer30 and the luminescent elements below the gas-barrier layer and canprevent the luminescent elements from deteriorating by the mechanicalshock.

Electronic apparatus are described according to the present invention.The electronic apparatus according to the present invention can includethe EL display (electro-optical device) as a display. FIG. 12 showsspecific examples of the electronic apparatus.

FIG. 12(a) is a perspective view showing one example of cellular phone.Reference numeral 1000 represents a main body of the cellular phone, andreference numeral 1001 represents a display using the EL display.

FIG. 12(b) is a perspective view showing one example of electronicapparatus of a wristwatch type. Reference numeral 1100 represents a mainbody of the wristwatch, and reference numeral 1101 is a display usingthe EL display.

FIG. 12(c) is a perspective view showing one example of a portableinformation-processing apparatus, such as a word processor or a personalcomputer. Reference numeral 1200 is an information processing apparatus,reference numeral 1202 is an input device such as key board, referencenumeral 1206 is a display using the EL display, and reference numeral1204 is a main body of the information processing apparatus.

These electronic apparatuses shown in FIGS. 12(a) to 12(c) are providedwith the display having the EL display (electro-optical device), hence,the lifetime of the luminescent elements of the EL display constitutingthe display is prolonged.

The gas-barrier property of the gas-barrier layer according to thepresent invention was confirmed by the following experiment.

Sample Preparation

Polyethylene terephthalate (PET; trade name [T60] manufactured by TORAYINDUSTRIES, INC. 188 μm in thickness) was used as a substrate. Materialsfor an electrode and a gas-barrier layer were deposited on the substrateas follows to prepare samples.

Preparation of an Inorganic Oxide Electrode (ITO) (Film-FormingCondition)

A magnetron DC sputtering apparatus was used for the film deposition.Indium tin oxide was used for target material. An ITO film of 100 nm inthickness was formed at a degree of vacuum of 0.4 Pa and in an argon andoxygen atmosphere.

Preparation of a Metal Electrode (Aluminum) (Film-Forming Condition)

A resistance heating vapor deposition apparatus was used for the filmdeposition. Highly pure aluminum was used as a material. An aluminumfilm of 25 nm in thickness was formed at a degree of vacuum of 1×10⁻⁵Pa.

Preparation of Silicon Compounds (Silicon Mono/Dioxide (SiOx), SiliconNitrides (SiNx), and Silicon Oxynitrides (SiOxNy)) as a Gas-BarrierLayer (Film-Forming Condition)

An electron cyclotron resonance (ECR) system was used for the filmdeposition. Silicon was used as a target material. A silicon compoundfilm of 10 to 150 nm in thickness was formed at degree of vacuum of 0.2Pa in an argon, an oxygen, and a nitrogen atmosphere. The type and theflow rate of the gas introduced were selected for each sample.

Measurement

Samples were examined for moisture permeability according to JIS-Z0208.The measurements (measured values) are shown as follows. Unit of themoisture permeability is g/m²·24 hours. Measurements were performed at60° C. and 90% RH. An untreated substrate and a substrate provided withonly a film of an electrode material were also examined for moisturepermeability for reference, the results are shown below. The moisturepermeability of films composed of only silicon compounds was calculated(converted) from the following equation. The results are also shown asreference values.

Conversion for the film composed of silicon compounds.(1/A)=(1/B)+(1/C)

wherein

A; measured values of (PET or PRT+ITO film)+silicon compounds film;

B; measured values of (PET or PRT+ITO film); and

C; calculated (converted) values of the films composed of siliconcompounds.

moisture permittivity film composed of sample composition measured valuesilicon compounds PET/ITO/SiOx 0.04 0.04 (film thickness is 70 nm)PET/ITO/SiNx 0.21 0.23 (film thickness is 40 nm) PET/ITO/SiOxNy 0.120.12 (film thickness is 40 nm) PET/SiOx 1.76 2.18 (film thickness is 70nm) PET/SiNx 0.45 0.47 (film thickness is 40 nm) PET/SiOxNy 0.29 0.30(film thickness is 40 nm) PET/Al/SiOx 0.41 0.81 PET 9.19 — PET/Al 0.81 —(film thickness is 25 nm) PET/ITO 3.13 — (film thickness is 100 nm)

Refractive index of silicon compounds were examined by an automaticellipsometer NARY-102 (manufactured by FIVE LAB Co., Ltd) at awavelength of 632 nm, resulting in 1.43 for SiOx, 1.99 for SiNx, and1.65 for SiOxNy. (The variations in composition of the SiOxNy allows therefractive index to change in any value).

Example 2

The moisture permeability was measure as in Example 1 while thethickness of the film of silicon compound was varied to determine therelationship between the film thickness and the moisture permeability.The results are shown below. Not only the measured value of the filmcomposed of silicon compounds (SiOx) which was not formed directly onthe substrate (PET), but also the example formed on the ITO layer (filmthickness of SiOx is 70 nm) is shown. FIG. 13 is a graph of theseresults.

moisture permittivity film composed of sample composition measured valuesilicon compounds PET/ITO/SiOx 0.04 0.04 (film thickness is 70 nm)PET/SiOx 9.14 1582.46 (film thickness is 10 nm) PET/SiOx 8.55 121.63(film thickness is 30 nm) PET/SiOx 3.68 6.14 (film thickness is 50 nm)PET/SiOx 1.76 2.18 (film thickness is 70 nm) PET/SiOx 0.47 0.49 (filmthickness is 100 nm) PET/SiOx 0.45 0.47 (film thickness is 150 nm)

As shown in FIG. 13, the measurements showed that the permeability ofthe films included in ITO film was significantly lower than thepermeability of the films merely composed of silicon compounds (SiOx) onthe substrate even if they have the same thickness. This showed that theformation of the films composed of silicon compounds (SiOx) on ITO film,rather than those formed directly on the substrate (PET), caused thefilm quality to be dense, improving gas-barrier property.

What is claimed is:
 1. An electro-optical device comprising: a base; afirst electrode disposed above the base; an insulating layer disposedabove the base, the insulating layer having an opening corresponding toa position at which the first electrode is formed; a second electrodedisposed above the first electrode and the insulating layer; a lightemitting layer disposed between the first electrode and the secondelectrode; a surrounding section disposed above the base, thesurrounding section being positioned outside the insulating layer; awiring disposed outside the surrounding section, the wiring beingelectrically connected to the second electrode; and a gas barrier layerdisposed on the second electrode, the gas barrier layer covering thesecond electrode, the surrounding section, and the wiring.
 2. Anelectro-optical device according to claim 1, wherein the gas battierlayer is formed such that the gas barrier layer reaches a peripheralarea outside the wiring.
 3. An electro-optical device according to claim2, wherein an edge of the gas barrier layer contacts with the base atthe peripheral area.
 4. An electro-optical device according to claim 2,wherein the base having a second insulating layer, and the edge of thegas barrier layer contacts with the insulating layer at the peripheralarea.
 5. An electro-optical device according to claim 1, wherein thewiring is electrically connected to the second electrode at the outerside of the surrounding section.
 6. An electro-optical device accordingto claim 1, wherein the gas barrier layer covers an entire surface ofthe second electrode, extending to an outer side of the second electrodeand contacting the base at the outer side of the second electrode, andthe gas barrier layer comprises an inorganic compound.
 7. Anelectro-optical device according to claim 6, wherein a portion of thegas barrier layer that contacts the base and the second electrode, thegas barrier layer comprises a silicon compound or a silicon oxidenitride, and at least a surface of the second electrode that contactsthe gas barrier layer comprises an inorganic oxide.
 8. An electronicapparatus comprising an electro-optical device according to claim
 1. 9.An electronic apparatus comprising an electro-optical device accordingto claim
 2. 10. An electronic apparatus comprising an electro-opticaldevice according to claim
 3. 11. An electronic apparatus comprising anelectro-optical device according to claim
 4. 12. An electronic apparatuscomprising an electro-optical device according to claim
 5. 13. Anelectronic apparatus comprising an electro-optical device according toclaim
 6. 14. An electronic apparatus comprising an electro-opticaldevice according to claim 7.